Conventionally, there has been known a game in which a player performs a game operation to the music. In such a game, a guide image is shown on a game screen to indicate to a player a reference timing at which the player should perform a game operation.
For example, Patent Document 1 discloses a technique for showing a guide image near the center of a game screen when a reference timing is coming, and then gradually moving the guide image so as to approach a determination position in accordance with the interval between the reference timing and the current timing, to thereby indicate the reference timing to the player.